After carefully evaluating the different tankless electric water heaters on the market, including different brands and models, we’ve selected the EcoSmart ECO 27 as the best quality unit for optimal efficiency and effectiveness at delivering hot water and maintaining continuous flow. When it comes to the best quality and value, the EcoSmart ECO 27 is a notch above the rest. The listed electric tankless water heaters stand apart from other water heaters because they are compact in design, which is great if space is a crucial factor, and they offer incredible energy efficiency that will save on electricity costs.